Cellulose ester and process of treating same.



No Drawing.

specification.

UNITED srr irEs Paras-Tormen- HARRY s. Mom; or sosron, MASSACHUSETTS,assmNoR T CHEMICAL rnonuo'rs' COMIANY, or :sos'ron, massacnusn'r'rs, ACORPORATION or MAINE.

Be it known that I, HARRY MoRK, of Boston, in the county of Suffolk andState of Massachusetts, have invented an Improve:

ment in Cellulose Esters and Processes of TreatingSame, of which thefollowing is a This invention relates to improvements in celluloseesters of the fatty acids, as cellulose acetate, and particularly to thedissolving orgelatinizing ofthese esters by new solvents. For manypurposes it is desirable to use a solvent of the ester from which thesolvent will evaporate rapidly, and, in case it is not practical torecover the solvent, the

-.;s,lution must contain a considerable amount of the est'erdissolvedin'it in'order tobe economical of solvent; as, for example, a

solution for coating and insulating fine wire used in the electricalart, ora solution for coating paper. a

Heretofore', acetone and chloroform, -.or mixtures of chloroform withrelatively small ercentages of methyl or ethyl alcohol, have 25 een theo y available highly volatile solvents force ulose acetate. Acetone isnot a concentrated solutions of that quality '0 cellulose acetate suchas will'make tough and flexible films. Chloroform and mixturesofchloroform with methyl or ethyl alcohol'dissolve such cellulose acetatereadily, and by either of'thfese solventsa solution containing aconsiderable quantity of cellulose acetate can be obtained; but the highcost of chloroform and its anesthetic properties rohibit its generaluse. 'FOIIHIC acid wil also dissolve cellulose acetate; and methylalcohol, 1n.;

mixtures with other solvents of cellulose acetate, such as acetylenetetrachlorid or chloroform, has a-latent solvent power for celluloseacetate, although alone it is a non-solvent.

,Now, I have discovered that methyl for-' mate, a hi hly' volatileliquid boilin -about;32 the condensation of methyl alcohol and at whichis the ester forme vby formic acid with the eliminationof water,. isalso a very excellent solventforcellulose acetate, and withit solutionsof cellulose.

acetatecan be made of a concentration comarable with those produced withchloroorm; for exam le, cellulose acetate of a,

uality from whlch can bedproduced tough films can be easily di' solve inmethyl for- Specification of Letters Patent. Application filed May 6,1910, Serial No. 559,7 2. 8.

- CELLULOSE ESTER AND PROGESS OF TREATING SAME.

Patented Oct. 11, 1910.

- mate in the pro ortion of at least twentyfour ounces of ce luloseacetate to one gallon of methyl formate. Methyl formate isa much morepowerful solvent for cellulose acetate than acetone, and it has distinctadvantages over chloroform. It is not neces--- Y sary or all purposesthat methyl formate be used alone as a solvent for the celluloseacetate, for it may be desirable to regulate or modify the rate ofevaporation of the solvent,'and this may be done by adding to the methylformate a less volatile solvent for the cellulose acetate, such. asacetylene tetrachlorid or phenol. To solutions of lulose acetate 1nmethyl formatecan be' added limited quantities of liquids which arenon-solvents of cellulose acetate; as, for example, benzol, or carbontetrachlorid, such non-solvents also acting to modify the rate ofevaporation and also serving as diluents.

I claim:

1. The method herein described of chang'- ing the'pliysical condition ofcellulose esters of the fatty acids, as cellulose acetate, whichconsists in dissolvin such esters in methyl formate, and then a ding tothe solution another solvent of the ester.

2. The method herein describedof changing the physical condition ofcellulose esters of the fatty acids, as cellulose acetate,whichconsists-in dissolving such ,esters in methyl formate, and then addingto the solvent a,

liquid which is a non-solvent of the ester.

3. The methodiherein' described of changing the physical condition ofcellulose esters of the'fatty acids, as cellulose acetate, whichconsists in dissolving such esters in methyl formate and anothersolvent, and then adding to the solution a liquid which is amonsolventof the ester.

4. A composition of matter consistin of a cellulose ester of a fattyvacid, as cellu ose acetate, dissolved inmethyl formate.

5. A composition of matter consisting. of

ose

a cellulose ester of a fatty acid, as cell acetate, dissolved in methylformate and an-' I other solvent.

6. .A composition of matter consistin of a cellulose ester of a fattyacid; as cell ose acetate, dissolved. in methyl orrnate and havinganother solvent for the ester, added to the solution.

7. composition or matter consisting of a'celliiiloseester of a fattyacid, as cellulose I acetate, dissolved in methyl formats, MR1 a ventfor the ester;

8. A composition of matterconsisting of 5" a, cellulose ester of afattyacid, as cellulose,

acetate, dissolved in methyl formate and'an other solvent, and a liquidadded to the soiution which is a; non-solvent for the ester.

' 9. A solvent for the cellulose esters of -%uid adoid to the solutionwhich is a non- Witnesses:

the fatty acids, as; cellulose acetate, consist- 16 in? of methylformats and another solvent. n testimony whereof, I have signed my nameto this specification, in. the presence of two subscribing witne's'ses'4 IRY Sr MORK.

B. J. NOYES,

H. B. DAYIS. I

